Battery protection circuit, charging and discharging circuit and battery pack

Abstract

The utility model discloses a battery protection circuit, a charge and discharge circuit and a battery pack, and relates to the field of batteries, a controllable switch is connected in series with an energy consumption module, the series-connected circuit is connected in parallel between two electrodes of a battery, and an overvoltage detection module controls the on or off of the controllable switch according to the trigger state of an overvoltage protection element in the battery. When the battery triggers two-section overvoltage hardware protection, the overvoltage detection module can control the controllable switch to be switched on, so that voltage at the two ends of the battery can be discharged through a series loop of the controllable switch and the energy consumption module, continuous accumulation of energy of a battery cell is avoided, and the battery cell is prevented from bulging. The controllable switch and the energy consumption module are arranged to serve as a discharge loop, so that under the condition that the battery triggers two-section overvoltage hardware protection, the energy of the battery cell can be quickly released through the energy consumption module, the safety problems that the battery cell is punctured by a structural part, the battery is burnt and ignited and the like are solved, and the safety and the reliability of the whole battery are improved.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a battery protection circuit, a charging and discharging circuit, and a battery pack. Background Technology

[0002] With the widespread use of batteries, the requirements for battery safety are becoming increasingly stringent. During charging, if the voltage continuously rises and exceeds a certain threshold, overcharging occurs. This not only damages battery performance and lifespan but can also lead to safety accidents. To prevent overcharging, overvoltage protection is designed for batteries, particularly using overvoltage protection components such as fuses to achieve hardware protection against overvoltage at two stages. When the battery voltage is too high and triggers this two-stage overvoltage hardware protection, the fuse will blow to cut off the battery's charging and discharging circuit, stopping the charging process. However, in this situation, the battery cells can no longer discharge to the outside through the charging and discharging circuit. Furthermore, when this two-stage overvoltage protection is triggered, the voltage of the internal battery cells remains very high, causing the cells to remain in a high-voltage, high-energy state, which can easily lead to safety problems such as cell bulging. Utility Model Content

[0003] The purpose of this invention is to provide a battery protection circuit, a charging and discharging circuit, and a battery pack. By setting a controllable switch and an energy dissipation module as a discharge circuit, the battery can quickly release the energy of the cell through the energy dissipation module when the overvoltage hardware protection of the second stage is triggered. This avoids safety problems such as structural components puncturing the cell and battery combustion and fire, thereby improving the overall safety and reliability of the battery.

[0004] To solve the above-mentioned technical problems, this utility model provides a battery protection circuit, including:

[0005] A controllable switch, the first end of which is connected to the first electrode of the battery;

[0006] The energy-consuming module has a first terminal connected to the second terminal of the controllable switch and a second terminal connected to the second electrode of the battery.

[0007] The overvoltage detection module has its output terminal connected to the control terminal of the controllable switch, and is used to control the controllable switch to conduct when the overvoltage protection element of the battery is detected to be triggered.

[0008] Optional, also includes:

[0009] The temperature detection module has its output connected to the input of the overvoltage detection module and is used to detect the temperature of the energy-consuming module.

[0010] The overvoltage detection module is also used to control the controllable switch to turn off when the temperature of the energy-consuming module is greater than the temperature threshold; and to control the controllable switch to turn on or off according to the triggering state of the overvoltage protection element when the temperature of the energy-consuming module is not greater than the temperature threshold.

[0011] Optionally, the temperature detection module is a thermistor, which is disposed on one side of the energy-consuming module. The first end of the thermistor is connected to the input terminal of the overvoltage detection module, and the second end is grounded.

[0012] Optional, also includes:

[0013] A heat-conducting module is provided between the thermistor and the energy-consuming module to transfer heat.

[0014] Optionally, the energy-consuming module includes several discharge resistors connected in series, and the first end of the series circuit is connected to the second end of the controllable switch, and the second end is connected to the second electrode of the battery.

[0015] Optionally, the energy-consuming module includes a switching switch and several energy-consuming sub-circuits. The switching switch includes several switching terminals that are connected to the several energy-consuming sub-circuits one by one. The fixed terminal of the switching switch is connected to the second terminal of the controllable switch, and the switching terminal is connected to the first terminal of the corresponding energy-consuming sub-circuit. The second terminal of the energy-consuming sub-circuit is connected to the second electrode of the battery. The energy consumption rate of each energy-consuming sub-circuit is different.

[0016] Optionally, the energy-consuming module is an energy storage device.

[0017] Optional, also includes:

[0018] The voltage detection module has a first input terminal connected to the first electrode of the battery, a second input terminal connected to the second electrode of the battery, and an output terminal connected to the control terminal of the controllable switch and the output terminal of the overvoltage detection module, respectively. It is used to detect the battery voltage of the battery and control the controllable switch to conduct when the battery voltage is greater than a preset threshold.

[0019] Optionally, the voltage detection module includes:

[0020] The first voltage divider resistor has its first end connected to the first electrode of the battery.

[0021] The second voltage divider resistor has its first end connected to the second end of the first voltage divider resistor, the control terminal of the controllable switch, and the output terminal of the overvoltage detection module, respectively, and its second end connected to the second electrode of the battery.

[0022] To solve the above-mentioned technical problems, this utility model also provides a battery charging and discharging circuit, including an overvoltage protection element, a charging and discharging switch, a control module, and a battery protection circuit as described above; the first terminal of the battery protection circuit is connected to the first electrode of the battery and the first terminal of the overvoltage protection element, and the second terminal is connected to the second electrode of the battery; the second terminal of the overvoltage protection element is connected to the first terminal of the charging and discharging switch; the output terminal of the control module is connected to the control terminal of the charging and discharging switch and the control terminal of the overvoltage protection element; the second terminal of the charging and discharging switch serves as the first external connection terminal of the battery, and the second electrode of the battery serves as the second external connection terminal of the battery;

[0023] The control module is used to control the charge / discharge switch to turn off when the battery voltage is greater than a first overvoltage threshold; and to trigger the overvoltage protection element when the battery voltage is greater than a second overvoltage threshold; wherein the second overvoltage threshold is greater than the first overvoltage threshold.

[0024] Optional, also includes:

[0025] The battery detection module, with its output terminal connected to the input terminal of the control module, is used to detect the battery voltage and / or charging current of the battery.

[0026] Optionally, the overvoltage protection element is a controllable fuse;

[0027] The battery charging and discharging circuit also includes:

[0028] An overvoltage switch has a first terminal connected to the control terminal of the controllable fuse, a second terminal connected to the second electrode of the battery, and a control terminal connected to the output terminal of the control module. It is used to conduct under the action of the control module when the battery voltage is greater than a second overvoltage threshold, so as to control the controllable fuse to blow.

[0029] To solve the above-mentioned technical problems, this utility model also provides a battery pack, including a battery cell and a charging and discharging circuit of the battery as described above, wherein a first end of the charging and discharging circuit of the battery is connected to a first electrode of the battery cell, and a second end is connected to a second electrode of the battery cell.

[0030] This invention provides a battery protection circuit, including a controllable switch, an energy dissipation module, and an overvoltage detection module. The controllable switch and the energy dissipation module are connected in series, and the series circuit is connected in parallel between the two electrodes of the battery. The overvoltage detection module controls the controllable switch to be on or off based on the triggering state of the overvoltage protection element in the battery. When the battery triggers the second stage of overvoltage hardware protection, the overvoltage detection module controls the controllable switch to be on, allowing the voltage across the battery terminals to be discharged through the series circuit of the controllable switch and the energy dissipation module, thereby preventing the continuous accumulation of energy in the battery cell and preventing the battery cell from bulging. By setting the controllable switch and the energy dissipation module as a discharge circuit, the battery can quickly release the energy in the battery cell through the energy dissipation module when the second stage of overvoltage hardware protection is triggered, avoiding safety problems such as structural components puncturing the battery cell and battery combustion and fire, thus improving the overall safety and reliability of the battery.

[0031] This utility model also provides a battery charging and discharging circuit and a battery pack, which have the same beneficial effects as the battery protection circuit described above. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of a battery protection circuit provided by this utility model;

[0034] Figure 2 A schematic diagram of another battery protection circuit provided by this utility model;

[0035] Figure 3 A schematic diagram of the output characteristic curve of a controllable switch provided by this utility model;

[0036] Figure 4 A schematic diagram of the charging and discharging circuit of a battery provided by this utility model;

[0037] Figure 5 This is a schematic diagram of the structure of a battery pack provided by this utility model. Detailed Implementation

[0038] The core of this utility model is to provide a battery protection circuit, a charging and discharging circuit, and a battery pack. By setting a controllable switch and an energy dissipation module as a discharge circuit, the battery can quickly release the energy of the cell through the energy dissipation module when the overvoltage hardware protection of the second stage is triggered. This avoids safety problems such as structural components puncturing the cell and battery combustion and fire, thereby improving the safety and reliability of the entire battery.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0040] Please refer to Figure 1 , Figure 1 This utility model provides a schematic diagram of a battery protection circuit; P+ represents the external positive terminal of the battery, P- represents the external negative terminal of the battery, BAT+ represents the positive terminal of the internal battery cell, and BAT- represents the negative terminal of the internal battery cell. To solve the above technical problems, this utility model provides a battery protection circuit, including:

[0041] The controllable switch Q0 has its first terminal connected to the first electrode of the battery;

[0042] The first terminal of the energy-consuming module 1 is connected to the second terminal of the controllable switch Q0, and the second terminal is connected to the second electrode of the battery.

[0043] The overvoltage detection module 2 has its output terminal connected to the control terminal of the controllable switch Q0, and is used to control the controllable switch Q0 to conduct when the overvoltage protection element of the battery is detected to be triggered.

[0044] Understandably, to prevent excessively high voltage across cell A01 when the overvoltage hardware protection of the second stage in the battery is triggered, this application further incorporates a protection circuit in the battery, including a controllable switch Q0, an energy dissipation module 1, and an overvoltage detection module 2. The overvoltage detection module 2 detects and determines the overvoltage hardware protection of the second stage in the battery, i.e., the triggering state of the overvoltage protection element in the battery, in real time. When the overvoltage protection element is triggered, the overvoltage detection module 2 simultaneously controls the controllable switch Q0 to conduct. After the controllable switch Q0 is conducted, the energy dissipation module 1 is connected in parallel between the two electrodes of the battery. The battery voltage can be discharged through the energy dissipation module 1, thereby reducing the battery voltage and preventing cell A01 from bulging due to continuous energy accumulation. This avoids safety events caused by excessively high energy in cell A01 and can also reduce the energy in cell A01 to prevent the safety event from worsening when a safety event occurs due to high voltage.

[0045] It should be noted that this application does not impose any special limitations on the specific types and implementation methods of the controllable switch Q0, energy consumption module 1, and overvoltage detection module 2. The controllable switch Q0 can be implemented using switching devices such as MOSFETs and transistors. The energy consumption module 1 can be implemented using energy-consuming devices such as resistors, MOSFETs, and conductive materials (conductive metals), or it can be implemented using energy storage devices such as capacitors. The overvoltage detection module 2 can establish a communication connection with the battery's own control module A03, such as the fuel gauge IC and secondary protection IC, to detect the trigger state of the overvoltage protection element. Alternatively, a control signal can be added to the battery's own control module A03, such as the fuel gauge IC and secondary protection IC, to control the controllable switch Q0, directly reusing the battery's own control module A03, such as the fuel gauge IC and secondary protection IC, to implement the overvoltage detection module 2. Alternatively, a microprocessor and AFE analog front-end can be used for precise data acquisition and control. This application does not impose any special limitations on the specific type of battery used or its implementation method; it can be a lithium battery, etc. The first electrode and the second electrode of a battery refer to the positive or negative electrode of the battery cell inside the battery. When the first electrode is the positive electrode, the second electrode is the negative electrode.

[0046] It is easy to understand that the overvoltage detection module 2 detects the electrical signal of the fuel gauge IC or the secondary protection IC. If the fuel gauge IC or the secondary protection IC triggers the fuse (FUSE), then simultaneously, this electrical signal can be transmitted as a detection signal to the controllable switch Q0, which then opens the discharge circuit to release energy. The overall self-dissipation current of a conventional battery is around 0.2-0.5mA, and energy release is very slow. However, with the discharge circuit designed in this invention, the energy of cell A01 can be released quickly through the energy dissipation module 1, and the current in the discharge circuit can reach the 150mA level. For a typical 4000mAh battery, this can bring its voltage down to a safe range within 24 hours, preventing combustion, fire, and explosion due to internal short circuits caused by self-expansion.

[0047] As a specific embodiment, please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of another battery protection circuit provided by this utility model; please refer to... Figure 3 , Figure 3 This invention provides a schematic diagram of the output characteristic curve. The energy-consuming module 1 is implemented using two resistors, R1 and R2, connected in series. A MOSFET is used as the controllable switch Q0, resulting in low cost and high versatility. Resistors R1 and R2 have resistance values ​​in the range of 50-200Ω, with variable internal resistance, and can be configured according to the current requirements during energy discharge. The MOSFET specifications can be set to Id>2A, VGS>1V, VDS>30V, and the package can use SOT23 / DFN3.3, etc. Currently, a PJA3244 MOSFET is used. The overvoltage detection module 2 can be implemented using a fuel gauge IC, a secondary protection IC, or other programmable ICs. It can detect the voltage signal of the fuse blown by the secondary protection IC. When the voltage signal of the blown fuse becomes high, the controllable switch Q0 is opened to discharge.

[0048] Simultaneously, the circuit incorporates a first voltage divider resistor Rf1 and a second voltage resistor, employing a 0.8MΩ + 10MΩ large resistor divider. The resistance is adjustable. When the cell voltage exceeds the set value, the controllable switch Q0 is automatically activated via the divided voltage signal, without requiring an IC voltage signal. For example... Figure 3 As shown, when the PJA3244 MOSFET is used to implement the controllable switch Q0, the controllable switch Q0 will be at V GS The MOSFET begins to conduct after the voltage exceeds 1.2V. At its maximum rated junction temperature TJ(max), and with the MOSFET surface temperature at 25°C or higher, the maximum permissible continuous DC current Id is 4.2A. Taking a 4.4V full-charge voltage system as an example, the total overvoltage limit is designed to be 4.55A. 4 = 18.2V, the voltage divider signal of the voltage divider circuit = Rf2 / (Rf1+Rf2) 18.2V = 1.348V, which is sufficient to effectively turn on the controllable switch Q0. When R1 = R2 = 100Ω, the resistance of the MOSFET in the discharge circuit is negligible at the milliohm level, and the current in the discharge circuit = 18.2V / (100+100Ω) = 91mA << 4.2A (MOSFET Id). When R1 = R2 = 50Ω, the resistance of the MOSFET in the discharge circuit is also negligible at the milliohm level, and the current in the discharge circuit = 18.2V / (50+50Ω) = 182mA << 4.2A (MOSFET Id), ensuring the safety of the MOSFET.

[0049] Furthermore, most current battery solutions on the market that trigger permanent overvoltage protection only fuse the internal charging and discharging circuit of the battery pack, without actually releasing energy from the A01 cell itself. Alternatively, after triggering permanent overvoltage protection, the fuse may not immediately fuse; instead, it may wait for the cell voltage to drop back to a lower level before triggering the permanent overvoltage protection. If the battery itself has low self-discharge and the user does not discharge the battery, it will remain in a high-voltage, high-energy state, posing unnecessary risks. For example, taking a 4000mAh 4-series-1 parallel battery with a full-charge voltage of 4.5V as an example, a conventional battery with a self-discharge of <0.6mA would require 3333 hours to discharge from 100% to 50%. However, using the safety hardware provided by this invention for discharge, it can be discharged to 50% capacity in 11 hours, reducing the high-voltage, high-energy time and avoiding safety risks.

[0050] It should be noted that the overvoltage detection module 2 can be controlled in hardware. After the battery triggers a permanent failure mode, the overvoltage signal is directly transmitted to the execution module A05 for energy release via the direct transmission of the fuse voltage signal from the fuel gauge IC or secondary protection IC. This hardware control method is not limited and can be designed based on the series and parallel ratio of the battery cells A01 in the actual project, according to the principle that battery pack voltage = cell voltage. The number of series circuits, combined with different resistors or MOSFETs, serves to receive IC electrical signals and activate the execution module A05. The overvoltage detection module 2 can also be implemented via software control. It uses the BMU to detect the current cell voltage, temperature, and current information. Before or after triggering the permanent failure mode, it can directly provide control signals or transmit signals through the AFE analog front end to activate or deactivate the execution module A05. This allows the battery to release energy earlier or simultaneously, and can be implemented within the microcontroller or the battery's fuel gauge IC.

[0051] It is understandable that there are no restrictions on the configuration of the execution module A05. Different design types can be achieved using integrated circuits with components such as MOSFETs, resistors, transistors, and conductive materials. The circuit current of the execution module A05 during release can be calculated based on the actual number of series and parallel connections of the battery cell A01 and Ohm's law (current I = voltage V / impedance R), allowing for the design of the execution module A05's circuit architecture according to different energy release requirements. The theoretical maximum discharge current value of the discharge circuit is also considered for different types of batteries. Since the utility model requires rapid energy release even after the FUSE in the main charging / discharging circuit of the battery body is blown, the energy release design is implemented at the positive and negative terminals of the battery cell A01. Generally, the execution module A05 can support a current release of less than or equal to 200mA. The discharge current and time definitions need to consider the following two aspects during design: First, the temperature specifications of all components and structural materials in the discharge circuit must not exceed the specifications of the components themselves; for example, the upper limit of the safety operating temperature for conventional PCB components is 130°C. On the other hand, after the energy of the current is released, the battery body is no longer subject to problems such as self-swelling, short circuit puncture caused by external pressure, and thus the combustion, fire and explosion of cell A01.

[0052] This invention provides a safe battery hardware protection circuit design. After a safety event such as overvoltage, and before safety issues such as abnormal battery swelling, foreign object puncture leading to internal short circuits, or fire occur, the overvoltage detection module 2 and execution module A05 designed within the hardware protection circuit release energy from cell A01. The overvoltage detection module 2 establishes a connection with the battery's own fuel gauge IC or secondary protection IC's fuse protection signal. After the battery triggers fuse protection, it synchronously activates the hardware discharge circuit, promptly releasing energy from cell A01. This prevents cell A01 from bulging due to aging, which could lead to structural components puncturing cell A01 and causing combustion or fire, thus providing higher battery safety.

[0053] Based on the above embodiments:

[0054] As an optional embodiment, it also includes:

[0055] The temperature detection module has its output connected to the input of the overvoltage detection module 2, and is used to detect the temperature of the energy consumption module 1.

[0056] The overvoltage detection module 2 is also used to control the controllable switch Q0 to turn off when the temperature of the energy-consuming module 1 is greater than the temperature threshold; and to control the controllable switch Q0 to turn on or off according to the triggering state of the overvoltage protection element when the temperature of the energy-consuming module 1 is not greater than the temperature threshold.

[0057] Considering that the entire protection circuit will be installed on the PCB board, the heat generated by the energy-consuming module 1 during energy discharge also needs to be taken into account. This is especially true when the energy-consuming module 1 uses consumable components such as a discharge resistor, which requires converting battery voltage into heat for discharge. This can lead to an increase in the PCB board temperature, potentially causing safety hazards. Therefore, a temperature detection module needs to be added to monitor the temperature near the energy-consuming module 1 in real time during energy discharge. When the temperature of the energy-consuming module 1 is low, the controllable switch Q0 can be turned on or off normally for energy discharge. However, when the temperature of the energy-consuming module 1 is high, the controllable switch Q0 needs to be temporarily turned off until the temperature drops before being turned on again for energy discharge. This application does not impose specific limitations on the specific value of the temperature threshold; it can be set and adjusted according to the actual application scenario. Similarly, this application does not impose specific limitations on the type and implementation method of the temperature detection module.

[0058] It should be noted that when the temperature exceeds the upper limit defined by the PCB or resistance, the entire protection circuit can still support intermittent discharge. Discharge and rest periods can be controlled by software settings in the overvoltage detection module 2. For example, when the PCB temperature reaches 100 degrees Celsius, the circuit rests, the controllable switch Q0 turns off, and energy dissipation stops. After the PCB temperature drops to 80 degrees Celsius, the controllable switch Q0 turns on again, and discharge continues. This application does not specifically limit the specific type and implementation method of the temperature detection module.

[0059] Specifically, by adding a temperature detection module, the heat generated during the energy dissipation process of the energy-consuming module 1 can be effectively avoided from affecting the normal operation of the entire circuit and the battery, thereby further improving the safety and reliability of the entire protection circuit and the battery.

[0060] As an optional embodiment, the temperature detection module is a thermistor, which is located on one side of the power consumption module 1. The first end of the thermistor is connected to the input terminal of the overvoltage detection module 2, and the second end is grounded.

[0061] As an optional embodiment, it also includes:

[0062] A heat-conducting module is provided between the thermistor and the energy-consuming module 1 to transfer heat.

[0063] It is understandable that the temperature detection module can be implemented using a thermistor located near the power consumption module 1, such as... Figure 2As shown, an NTC resistor is used. To ensure the thermistor can effectively and promptly detect the temperature near the power-consuming module 1, a thermally conductive module made of thermally conductive materials such as thermally conductive adhesive can be used to connect the thermistor and the power-consuming module 1. This application does not impose any specific limitations on the specific types and implementation methods of the thermistor and the thermally conductive module.

[0064] As a specific embodiment, the discharge device can be implemented using a metal conductor, providing strong heat dissipation. Furthermore, in the structural design, the thermally conductive adhesive on the circuit board can connect to the NTC temperature detection circuit. This allows the battery's existing functionality to report high-temperature information to the host battery without requiring additional components or circuits, thereby achieving current limiting or charging stop at the host end and preventing further energy accumulation in the A01 cell inside the battery. For example... Figure 2 As shown, the NTC uses a 10K, B=3435K specification and is connected to the energy-consuming devices R1 and R2 through thermally conductive adhesive. When the temperature is very high, the NTC feedback signal causes the overvoltage detection module 2 to output 0V to turn off the controllable switch Q0, stop the discharge, and wait for the temperature to drop before discharging again to avoid continuous discharge that could cause the device to exceed its operating temperature.

[0065] Specifically, by setting up a thermistor and a heat-conducting module, the overvoltage detection module 2 can effectively control the operation of the discharge circuit based on the temperature near the energy-consuming module 1, thereby avoiding the impact of the heat generated by the energy-consuming module 1 on the protection circuit and the normal operation of the entire battery. The structure is simple and easy to implement, which is conducive to the simple implementation of the entire protection circuit.

[0066] As an optional embodiment, the energy-consuming module 1 includes several discharge resistors connected in series, and the first end of the series circuit is connected to the second end of the controllable switch Q0, and the second end is connected to the second electrode of the battery.

[0067] As an optional embodiment, the energy-consuming module 1 includes a switching switch and several energy-consuming sub-circuits. The switching switch includes several switching terminals that are connected to the several energy-consuming sub-circuits one by one. The fixed terminal of the switching switch is connected to the second terminal of the controllable switch Q0, and the switching terminal is connected to the first terminal of the corresponding energy-consuming sub-circuit. The second terminal of the energy-consuming sub-circuit is connected to the second electrode of the battery. The energy consumption rate of each energy-consuming sub-circuit is different.

[0068] As an optional embodiment, the energy-consuming module 1 is an energy storage device.

[0069] It is easy to understand that the energy dissipation module 1 can be implemented using a bleed resistor. At the same time, the energy dissipation efficiency can be improved by setting multiple bleed resistors in series to dissipate energy simultaneously. This application does not make any special restrictions on the specific type and implementation method of each bleed resistor. Its specific resistance value can also be adjusted according to the actual application. The resistance value of each bleed resistor can be implemented using resistors of different types or with different resistance values.

[0070] To adapt to various application scenarios, a switching switch and an energy-consuming sub-circuit can also be used to implement the energy-consuming module 1. The overvoltage detection module 2 can switch the switching switch to different switching terminals according to actual application requirements, control one of the energy-consuming sub-circuits to conduct, thereby adjusting the energy-consuming sub-circuit connected in series with the controllable switch Q0, thus meeting the requirements for different energy discharge rates in different scenarios. This application does not make any special limitations on the specific type and implementation method of the switching switch and each energy-consuming sub-circuit.

[0071] It is understandable that energy consumption module 1 can also be implemented using energy storage devices. When the controllable switch Q0 is turned on, the battery voltage is high, charging the energy storage device. This allows the energy stored in the energy storage device to be released from the battery. This application does not impose any specific limitations on the specific type or implementation method of the energy storage device, and its energy storage capacity can be set and adjusted according to different battery types and capacities. Furthermore, the battery can be combined with other systems to implement energy consumption module 1. For example, when the device containing the battery has a heating function, a heating device, such as a heating resistor, can be connected in series in the discharge circuit to simultaneously release battery energy and heat the device.

[0072] Specifically, there are multiple options for energy-consuming devices, which can be set and adjusted according to the actual application scenario of the protection circuit. They are highly flexible and have a wide range of applications. The three embodiments provided have simple structures and are easy to implement, which is conducive to the simple implementation of the entire protection circuit.

[0073] As an optional embodiment, it also includes:

[0074] The voltage detection module has a first input terminal connected to the first electrode of the battery, a second input terminal connected to the second electrode of the battery, and an output terminal connected to the control terminal of the controllable switch Q0 and the output terminal of the overvoltage detection module 2, respectively. It is used to detect the battery voltage and control the controllable switch Q0 to conduct when the battery voltage is greater than a preset threshold.

[0075] Considering the possibility of high cell voltage during battery application, but failure of the fuel gauge IC and secondary protection IC, a voltage detection module is further included in the protection circuit as an alternative control method for the controllable switch Q0. When the cell voltage is high, but the fuel gauge IC and secondary protection IC fail, the voltage detection module can detect the excessively high battery voltage and control the controllable switch Q0 to conduct. At this time, the discharge circuit can open to release energy and prevent the continuous accumulation of energy in cell A01, which could lead to combustion and fire. Both the overvoltage detection module 2 and the voltage detection module controlling the controllable switch Q0 can coexist; whichever condition is met first will be activated. Alternatively, either the overvoltage detection module 2 or the voltage detection module can be used independently to control the controllable switch Q0. This application does not impose specific limitations on the specific value of the preset threshold. It can be determined based on parameters such as the battery's hardware overvoltage protection value, common full-charge voltage, and platform voltage, combined with the customer's required overvoltage design value.

[0076] Specifically, by setting up a voltage detection module, the controllable switch Q0 is turned on, which is another way to control whether the discharge circuit discharges energy. This allows the voltage detection module to discharge energy when the battery voltage is too high even if the secondary hardware protection of the battery fails, further avoiding battery swelling and the safety hazards caused by swelling, and improving the overall safety and reliability of the battery.

[0077] As an optional embodiment, the voltage detection module includes:

[0078] The first voltage divider resistor Rf1 has its first terminal connected to the first electrode of the battery.

[0079] The second voltage divider resistor Rf2 has its first end connected to the second end of the first voltage divider resistor Rf1, the control end of the controllable switch Q0, and the output end of the overvoltage detection module 2, respectively, and its second end connected to the second electrode of the battery.

[0080] It is understandable that the voltage detection module can be implemented using a voltage divider circuit consisting of a first voltage divider resistor Rf1 and a second voltage divider resistor Rf2. The first electrode is usually the positive terminal of the battery. The two voltage divider resistors combined can divide the voltage of the positive terminal of the battery and output it to the control terminal of the controllable switch Q0, thereby realizing the control of the controllable switch Q0. Figure 2 As shown, a large resistor divider of 0.8MΩ + 10MΩ is used, and the resistance is adjustable. When the cell voltage is higher than the set value, the controllable switch Q0 is automatically turned on by the voltage divider signal without the need for an IC voltage signal. This application does not make any special restrictions on the specific type and implementation method of the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2, and their resistance values ​​can also be adjusted according to actual application requirements.

[0081] It should be noted that the entire protection circuit consists of two parts: a detection module and an execution module A05. The detection module is mainly an overvoltage detection module 2, and the execution module A05 includes a controllable switch Q0 and an energy consumption module 1. When the battery is continuously charging, if the cell voltage becomes too high and triggers the overvoltage failure protection point of the battery fuel gauge IC or secondary protection IC, the battery will melt the fuse FUSE connected in series in the main circuit, i.e., the charging / discharging circuit A04, preventing the battery from discharging. The detection module can collect the voltage signal that the current fuel gauge IC or secondary protection IC controls to melt the FUSE, or directly activate the execution module A05 when the voltage at the cell A01 terminal is higher than a set value. Alternatively, if the battery temperature is too high and triggers the over-temperature failure protection point of the battery fuel gauge IC or secondary protection IC, the battery will melt the FUSE in the main circuit, preventing further discharge. This detection module can collect the current voltage signal of the fuel gauge IC, thereby activating the execution module A05. Alternatively, when the cell voltage exceeds a specific value and both the fuel gauge IC and the secondary protection IC fail, making it impossible to obtain their voltage signals, the execution module A05 can be actively activated to reduce the probability of safety incidents. Upon receiving a signal from the detection module, the execution module A05 activates and rapidly releases battery energy through the energy dissipation module 1. Simultaneously, the heat energy signal during the release process is converted into a digital signal via the temperature detection circuit of the fuel gauge IC and reported to the host unit A20 via the battery pack's communication bus.

[0082] Specifically, the voltage detection module can be implemented directly through a voltage divider circuit. The voltage divider circuit's voltage division characteristics and output voltage are used to effectively control the controllable switch Q0. The structure is simple and easy to implement. The components used are low-cost and small in size, which is conducive to the simple implementation of the entire protection circuit.

[0083] Please refer to Figure 4 , Figure 4 This utility model provides a schematic diagram of a battery charging and discharging circuit. To solve the above-mentioned technical problems, this utility model also provides a battery charging and discharging circuit, including an overvoltage protection element, a charging and discharging switch, a control module A03, and the aforementioned battery protection circuit. The first terminal of the battery protection circuit is connected to the first electrode of the battery and the first terminal of the overvoltage protection element, respectively, and the second terminal is connected to the second electrode of the battery. The second terminal of the overvoltage protection element is connected to the first terminal of the charging and discharging switch. The output terminal of the control module A03 is connected to the control terminal of the charging and discharging switch and the control terminal of the overvoltage protection element, respectively. The second terminal of the charging and discharging switch serves as the first external connection terminal of the battery, and the second electrode of the battery serves as the second external connection terminal of the battery.

[0084] The control module A03 is used to control the charge / discharge switch to turn off when the battery voltage is greater than the first overvoltage threshold; and to trigger the overvoltage protection element when the battery voltage is greater than the second overvoltage threshold; the second overvoltage threshold is greater than the first overvoltage threshold.

[0085] As an optional embodiment, it also includes:

[0086] The battery detection module A02 has its output connected to the input of the control module A03 and is used to detect the battery voltage and / or charging current.

[0087] As an optional embodiment, the overvoltage protection element is a controllable fuse (FUSE).

[0088] The battery's charging and discharging circuit also includes:

[0089] The overvoltage switch Q3 has its first terminal connected to the control terminal of the controllable fuse FUSE, its second terminal connected to the second electrode of the battery, and its control terminal connected to the output terminal of the control module A03. It is used to conduct under the action of the control module A03 when the battery voltage is greater than the second overvoltage threshold, so as to control the controllable fuse FUSE to blow.

[0090] It is understood that a control module A03 is installed inside the battery to control the charging and discharging process. Control module A03 can control the on / off state of the charging / discharging switch according to the battery application requirements, thereby controlling whether the battery can be charged and discharged. Simultaneously, control module A03 provides overvoltage protection based on the real-time battery voltage. Overvoltage protection is divided into two stages: the first stage is achieved by controlling the charging / discharging switch to open, and the second stage is achieved by controlling the overvoltage protection element to switch the charging / discharging circuit A04. This application does not specifically limit the specific values ​​of the first and second overvoltage thresholds. This application also does not specifically limit the specific types and implementation methods of the charging / discharging switch, overvoltage protection element, and control module A03 in the battery. Figure 4 As shown, the charge / discharge switch is implemented using MOSFETs Q1 and Q2, and the overvoltage protection element is implemented using a fuse. The control module A03 includes a fuel gauge IC (microcontroller) and a secondary protection IC. The fuel gauge IC can determine parameters such as battery voltage through the battery detection module A02 built into the battery. It can also use the resistor R-sense connected in series in the charge / discharge circuit A04 to detect the charging current or discharging current and determine whether overvoltage protection is required. When two-stage overvoltage protection is required, the fuel gauge IC sends a corresponding signal to inform the secondary protection IC. The secondary protection IC outputs a voltage signal to control the overvoltage switch Q3 to conduct, thereby controlling the fuse to blow. Figure 4The illustration uses a single battery cell as an example. In other embodiments, the number of cells in the battery pack is not limited; it can be a single cell or multiple cells, without a specific series-parallel ratio. There are also no limitations on the type of battery pack used; it can be a power source for devices such as mobile phones, laptops, and small power tools.

[0091] For a description of the battery charging and discharging circuit provided by this utility model, please refer to the above-described embodiment of the battery protection circuit; this utility model will not be described again here.

[0092] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of a battery pack provided by this utility model. To solve the above-mentioned technical problems, this utility model also provides a battery pack, including a battery cell A01 and a charging and discharging circuit of the battery as described above. The first end of the charging and discharging circuit of the battery is connected to the first electrode of the battery cell A01, and the second end is connected to the second electrode of the battery cell A01.

[0093] For an introduction to the battery pack provided by this utility model, please refer to the above-described embodiments of the battery protection circuit and the battery charging and discharging circuit. This utility model will not be described in detail here.

[0094] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should also be noted that in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0095] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery protection circuit, characterized in that, include: A controllable switch, the first end of which is connected to the first electrode of the battery; The energy-consuming module has a first terminal connected to the second terminal of the controllable switch and a second terminal connected to the second electrode of the battery. The overvoltage detection module has its output terminal connected to the control terminal of the controllable switch, and is used to control the controllable switch to conduct when the overvoltage protection element of the battery is detected to be triggered.

2. The battery protection circuit as described in claim 1, characterized in that, Also includes: The temperature detection module has its output connected to the input of the overvoltage detection module and is used to detect the temperature of the energy-consuming module. The overvoltage detection module is also used to control the controllable switch to turn off when the temperature of the energy-consuming module is greater than the temperature threshold; and to control the controllable switch to turn on or off according to the triggering state of the overvoltage protection element when the temperature of the energy-consuming module is not greater than the temperature threshold.

3. The battery protection circuit as described in claim 2, characterized in that, The temperature detection module is a thermistor, which is located on one side of the power consumption module. The first end of the thermistor is connected to the input terminal of the overvoltage detection module, and the second end is grounded.

4. The battery protection circuit as described in claim 3, characterized in that, Also includes: A heat-conducting module is provided between the thermistor and the energy-consuming module to transfer heat.

5. The battery protection circuit as described in claim 1, characterized in that, The energy-consuming module includes several discharge resistors, which are connected in series. The first end of the series circuit is connected to the second end of the controllable switch, and the second end is connected to the second electrode of the battery.

6. The battery protection circuit as described in claim 1, characterized in that, The energy-consuming module includes a switching switch and several energy-consuming sub-circuits. The switching switch includes several switching terminals that are connected one-to-one with the several energy-consuming sub-circuits. The fixed terminal of the switching switch is connected to the second terminal of the controllable switch, and the switching terminal is connected to the first terminal of the corresponding energy-consuming sub-circuit. The second terminal of the energy-consuming sub-circuit is connected to the second electrode of the battery. The energy consumption rate of each energy-consuming sub-circuit is different.

7. The battery protection circuit as described in claim 1, characterized in that, The energy-consuming module is an energy storage device.

8. The battery protection circuit according to any one of claims 1 to 7, characterized in that, Also includes: The voltage detection module has a first input terminal connected to the first electrode of the battery, a second input terminal connected to the second electrode of the battery, and an output terminal connected to the control terminal of the controllable switch and the output terminal of the overvoltage detection module, respectively. It is used to detect the battery voltage of the battery and control the controllable switch to conduct when the battery voltage is greater than a preset threshold.

9. The battery protection circuit as described in claim 8, characterized in that, The voltage detection module includes: The first voltage divider resistor has its first end connected to the first electrode of the battery. The second voltage divider resistor has its first end connected to the second end of the first voltage divider resistor, the control terminal of the controllable switch, and the output terminal of the overvoltage detection module, respectively, and its second end connected to the second electrode of the battery.

10. A charging and discharging circuit for a battery, characterized in that, The device includes an overvoltage protection element, a charge / discharge switch, a control module, and a protection circuit for a battery as described in any one of claims 1 to 9. The first terminal of the battery protection circuit is connected to the first electrode of the battery and the first terminal of the overvoltage protection element, respectively; the second terminal is connected to the second electrode of the battery; the second terminal of the overvoltage protection element is connected to the first terminal of the charge / discharge switch; the output terminal of the control module is connected to the control terminal of the charge / discharge switch and the control terminal of the overvoltage protection element, respectively; the second terminal of the charge / discharge switch serves as the first external connection terminal of the battery; and the second electrode of the battery serves as the second external connection terminal of the battery. The control module is used to control the charge / discharge switch to turn off when the battery voltage is greater than a first overvoltage threshold; and to trigger the overvoltage protection element when the battery voltage is greater than a second overvoltage threshold; wherein the second overvoltage threshold is greater than the first overvoltage threshold.

11. The charging and discharging circuit of the battery as described in claim 10, characterized in that, Also includes: The battery detection module, with its output terminal connected to the input terminal of the control module, is used to detect the battery voltage and / or charging current of the battery.

12. The charging and discharging circuit of the battery as described in claim 10, characterized in that, The overvoltage protection element is a controllable fuse; The battery charging and discharging circuit also includes: An overvoltage switch has a first terminal connected to the control terminal of the controllable fuse, a second terminal connected to the second electrode of the battery, and a control terminal connected to the output terminal of the control module. It is used to conduct under the action of the control module when the battery voltage is greater than a second overvoltage threshold, so as to control the controllable fuse to blow.

13. A battery pack, characterized in that, The battery includes a battery cell and a charging / discharging circuit for a battery as described in any one of claims 10 to 12, wherein a first terminal of the charging / discharging circuit is connected to a first electrode of the battery cell, and a second terminal is connected to a second electrode of the battery cell.

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